Brush-holder for dynamo-electric machines.



W. T. HENSLEY. BRUSH HOLDER FOR DYNAMO ELECTRIC MACHINES.

APPLICATION FILED MAY 4, 1908.

949,072. Patented Feb. 15,1910.

1 1 m ENTOR ATTORNEY UNITED STATES PATENT oEEIoE.

ASSIGNMENTS, TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, OF EASTPITTSBURG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

BRUSH-HOLDER FOR DYNAMO-ELECTRIC MACHINES.

Specification of Letters Patent.

Application filed May 4, 1908.

Patented Feb. 15, 1910.

Serial No. 430,?89.

To all whom it may concern:

Be it known that I, VVILLIAM T. HENsLEY, a citizen of the United States,and a resident of ilkinsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in Brush-Holders for Dynamo-Electric Machines, of which the following is aspecification.

My invention relates to brush holders for dynamo-electric machines andit has for its object to provide an improved pressure mechanism and abrush engaging finger therefor.

A well known type of brush holder comprises a box, a supporting armtherefor and a pressure mechanism comprising a brushengaging finger andresilient means for pressing the extremity of the finger against the topof the carbon brush. On account of slight unavoidable irregularities inthe outer surfaces of commutators, engaging contact brushes arepreferably mounted so that they are free to adjust themselves in the boxand to follow these irregularities.

According to my present invention, I provide an improved brush engagingfinger which produces the necessary pressure between the brush and thecommutator surface and at the same time is so constructed. that aconsiderable movement of the brush in its supporting box is permittedwithout necessitating any relative movement between the engaging end ofthe finger and the top of the brush. By this means, a freer movement ofthe brush is permitted since the opposing forces of friction, whichusually exist, are avoided.

Figure 1 of the accompanying drawings is a side elevation, partially insection, of a brush holder constructed in accordance with my inventionand Fig. 2 is an end elevation of a portion of the brush holder shown inFig. 1.

Referring to the drawings, the device here illustrated comprises acarbon block or brush 1, a holder or box 2 in which the brush is movablymounted, a supporting arm 3 which is integral with the box 2 and is provided with a projection 4 by which it may be secured to the frame of adynamo-electric machine and a pressure mechanism 5. The pressuremechanism comprises a shaft 6 which is attached to the arm 3, a sleeve 7rotatably mounted on the shaft 6 and provided with a ratchet wheel 8, abrush-engaging fin.- ger 9 rotatably mounted on the sleeve 7 andprovided with a pawl 10 to engage the ratchet wheel 8. A spiral spring11 is coiled around the sleeve 7, its inner extremity engaging alongitudinal groove 12 in the sleeve 7 and its outer extremity 13 beingheld stationary by engagement with a hooked projection 14 on the arm 3.The finger 9 is made up of two parts one of which is built up of aresilient spring 15 which is bent into an arc of relatively largeradius, a flexible shunt. 16 of copper or other good conducting materialand a contact member 17 which engages the top of the brush 1 and isriveted or otherwise secured to the parts 15 and 16. The arrangement ofparts is such that a ma terial downward pressure is exerted by theresilient spring 15 upon the top of the brush 1 while, at the same time,the length of the are in which the spring is bent is so great as topermit a material adjustment of the brush 1 in the box 2 withoutnecessitating any relative movement between the contact member 17 andthe top of the brush. The second part 18 of the finger 9 is compa'atively rigid and is bent into an arc of relatively short radius withinthe are formed by the spring 15. This rigid finger is intended foremergencies and acts in the ordinary manner against the top of the brush1 in case the spring 15 is broken or bent out of shape.

It is to be understood that structural modifications may be effectedwithin the spirit and scope of my invention.

I claim as my invention:

1. A brush-holder for dynamo-electricmachines comprising a box in whicha brush is movably mounted, a looped resilient brushengaging finger, asubstantially rigid emergency finger within the loop of the resilientfinger and means for creating a pressure be tween the extremity of thebrush-engaging finger and the outer end of the brush.

2. Abrushholder for dynamo-electric machines comprising a box, a carbonbrush movably supported therein, a supporting arm integral with the box,a resilient brushengaging finger bent into the form of an open ring orloop, a rigid finger projection within the loop of the resilient fingerand a pressure mechanism for forcing the extremity of the resilientfinger into engagement with the outer end of the brush.

Z A brush-holder for dynamo-electricmachines comprising a box, a carbonbrush movabl r supported therein, a supporting arm integral with thebox, a resilient brushengaging finger bent into the form of an open ringor loop, a rigid finger projection Within the loop of the resilientfinger and an adjustable pressure mechanism for forc ing the extremit ofthe resilient finger into engagement with the outer end of the brush.

l. A bruslrholder for dynamo-electricma chines comprising a box. acarbon brush movably supported therein, a supporting arm integral Withthe box, a resilient brushengaging finger bent into the form of an openring or loop, a rigid finger projection within the loop of the resilientfinger and a pressure mechanism for forcing the extre1n ity ot' theresilient finger into engagement with the outer end of the brush, saidmechanism comprising a shaft, a sleeve rotatable on the shaft, a spiralspring secured to the sleeve at one end and to the supporting arm at theother end and adjustable means for connecting the inner ends of thefingers to the sleeve.

5. A brush-holder for dynamo-electric machines comprising a box, acarbon brush therein, a resilient brush-engaging finger comprising anearly closed loop at its free end and a brush-engaging member fastenedto the end of the loop portion whereby morement of the brush in the box,without involving relative movementbetween the engaging surfaces of thebrush and the engaging member, is permitted, and a pressure mechanismacting upon said finger to force said brushengaging member against theend of the brush.

In testimony whereof, I have hereunto subscribed my name this 28th dayol April, 1908.

VILLIAM T. HENSLEY.

Vitnesses Fnxxn A. Rnw, Bmxnr HIxEs.

